In the state of the art of material processing using electron beams, it is known to drive the deflection coil of the electron beam gun using analog amplifiers that have a high-level signal control frequency of up to 100 kHz. Using known techniques, a precision of the electron beam of 1% (i.e. 1% per mil or 0.1%) can be achieved. However, known analog amplifiers tend to oscillate, over-shoot and level-out during signal level changes/transitions.
U.S. Pat. No. 2,989,614 discloses an electron beam system, which utilizes a current-adding array in order to convert a digital signal into an analog signal. This analog signal must then be amplified using a power analog amplifier before the amplified value is supplied to the deflection coil. Therefore, this known electron beam system suffers from the above-noted problems.
It is further known in the state of the art to display back-scattered electrons, which are back scattered by a work piece processed by the electron beam, on an indicator, such as a display, or to plot the back-scattered electrons using an appropriate recording apparatus, both in a chronologically synchronized manner.